An old and discarded treatment for anthrax infection could be manufactured in a matter of weeks and help save many lives.
The vaccine-like antidote is "anthrax antitoxin." It's cheap to make and can be used as an experimental treatment in addition to the use of antibiotics. The antitoxin treatment can quickly act against the infection.
As this column has pointed out, there are serious scientific questions about whether the anthrax vaccine can effectively prevent an infection in humans via the inhalation of spores. (See archive, right.) And antibiotics used after an exposure to anthrax work before symptoms appear. They are not likely to affect a toxin produced by the anthrax bacterium already working in the body and producing symptoms.
Given mounting concerns about a possible wider-scale attack with anthrax, it only makes sense to pull together whatever treatments might prove to be valuable. The science on anthrax antitoxin suggests it can be. Anthrax antitoxin stopped being used as effective antibiotics became available.
China Uses it Already
A 1999 review article on anthrax in the New England Journal of Medicine concludes that anthrax antitoxin has potential but that "unfortunately, antitoxin preparations are not currently available in the United States," Dr. Meryl Nass, associated with Parkview Hospital in Brunswick, Maine, who has testified on numerous occasions before congressional committees looking into anthrax prevention and treatment, also wrote in 1999 in the Infectious Disease Clinics of North America, that "multiple case reports as well as experimental studies have documented some benefit of this approach."
Nass told me that China uses an anthrax antitoxin, along with antibiotics, as standard treatment, and that the United States could either buy it from the Chinese or drug companies could easily start their own production.
What an Antitoxin Is
Antitoxins are typically made by injecting a toxin in increasing amounts into an animal. Horses have often been used for this purpose. The animal then produces antibodies to the toxin. These antibodies are then extracted from the animal's blood and purified. The goal in injecting the antibodies into an infected human is to have the antibodies (the antitoxin) neutralize the toxin that is damaging the individual's body. The antibody effect is temporary, but there is evidence that it works.
In the case of anthrax, it might be prudent to inject the animal with a variety of strains, which is what China has done.
This idea has been around since 1890, when Emil Adolph von Behring, a German doctor, showed that animals immune to diphtheria had antibodies to the toxin that diphtheria bacteria produce. Antitoxins began to be used four years later to treat the disease.
Here's the problem with antitoxins: It means injecting foreign animal proteins into humans. That can cause the human immune system to become hypersensitive to the antitoxin, usually several weeks after the injection. This is referred to as "serum sickness."
Side effects, lasting one to two weeks, can be numerous, including fever, muscle pain, lymph node swelling, swelling at the injection site, neurological problems, chest pain and breathing difficulties.
Nass allows that the side effects could be nasty because the anthrax antitoxin would be crude, but that in a pinch it would be better to endure them than face the possibility of death.
The antitoxin would be administered when it was likely the antibiotic treatment was too late — if, for example, someone had had symptoms and didn't initially know it was anthrax but now was in a struggle to stay alive. At that point, the antibiotic route, alone, probably wouldn't be effective.
The making of the antitoxin shouldn't be terribly complicated for a well-equipped drug company because the antibodies produced, say, in a horse, could be available in a matter of weeks.
As for approval, the Food and Drug Administration has a mandate in event of emergency to fast track a review of potential treatments. In such a case, anyone given the medication would be offered a consent form to sign.
Meanwhile, there are efforts under way to produce a cleaner antidote to anthrax.
Researchers at Harvard Medical School have, for example, created a synthetic compound that attacks a lethal toxin produced by the anthrax bacterium. But since it has only been tested in rats, we'll have to wait for the results of further research.
What we obviously need is a fast-track anthrax antitoxin program to get under way and strong support for researchers hoping to eventually produce an effective and safe antidote to anthrax.